Am Montag, 14. Oktober 2013, 16:12:24 schrieb Stephan Mueller: Hi Sandy, > >(PS: I am aware that in case none of the individual bits would contain >one full bit of entropy, the folding operation may --mathematically >spoken-- not deliver one full bit of entropy. However, after speaking >with a mathematician, that slight inconsistency is ok, if I can show >that the distribution of the folded bit is 50% zeros and 50% ones. That >is what I did in section 5.2.1. Thus, the conclusion is that I receive >one bit of entropy after the folding loop.) One followup on this issue: if one believes that he has a problem with that consideration, he can initialize the CPU Jitter RNG with an oversampling rate. That rate simply performs the folding operation 64 times oversampling rate. To fill the entropy pool completely once, the RNG needs 64 time deltas which are folded into the one bit. All the oversampling rate now does is to calculate more than once the complete entropy pool. For example, when you set the oversampling rate to 2, you need twice as long for the random value as each bit the random value is calculated twice. And the two independent 64 bit random values are simply XORed together. You can set the oversampling rate to any value above 1. Ciao Stephan -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
